1 /*- 2 * Copyright (c) 1982, 1986, 1989, 1993 3 * The Regents of the University of California. All rights reserved. 4 * (c) UNIX System Laboratories, Inc. 5 * All or some portions of this file are derived from material licensed 6 * to the University of California by American Telephone and Telegraph 7 * Co. or Unix System Laboratories, Inc. and are reproduced herein with 8 * the permission of UNIX System Laboratories, Inc. 9 * 10 * Redistribution and use in source and binary forms, with or without 11 * modification, are permitted provided that the following conditions 12 * are met: 13 * 1. Redistributions of source code must retain the above copyright 14 * notice, this list of conditions and the following disclaimer. 15 * 2. Redistributions in binary form must reproduce the above copyright 16 * notice, this list of conditions and the following disclaimer in the 17 * documentation and/or other materials provided with the distribution. 18 * 4. Neither the name of the University nor the names of its contributors 19 * may be used to endorse or promote products derived from this software 20 * without specific prior written permission. 21 * 22 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 23 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 24 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 25 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 26 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 27 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 28 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 29 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 30 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 31 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 32 * SUCH DAMAGE. 33 * 34 * @(#)sys_generic.c 8.5 (Berkeley) 1/21/94 35 */ 36 37 #include <sys/cdefs.h> 38 __FBSDID("$FreeBSD$"); 39 40 #include "opt_capsicum.h" 41 #include "opt_compat.h" 42 #include "opt_ktrace.h" 43 44 #include <sys/param.h> 45 #include <sys/systm.h> 46 #include <sys/sysproto.h> 47 #include <sys/capsicum.h> 48 #include <sys/filedesc.h> 49 #include <sys/filio.h> 50 #include <sys/fcntl.h> 51 #include <sys/file.h> 52 #include <sys/lock.h> 53 #include <sys/proc.h> 54 #include <sys/signalvar.h> 55 #include <sys/socketvar.h> 56 #include <sys/uio.h> 57 #include <sys/kernel.h> 58 #include <sys/ktr.h> 59 #include <sys/limits.h> 60 #include <sys/malloc.h> 61 #include <sys/poll.h> 62 #include <sys/resourcevar.h> 63 #include <sys/selinfo.h> 64 #include <sys/sleepqueue.h> 65 #include <sys/syscallsubr.h> 66 #include <sys/sysctl.h> 67 #include <sys/sysent.h> 68 #include <sys/vnode.h> 69 #include <sys/bio.h> 70 #include <sys/buf.h> 71 #include <sys/condvar.h> 72 #ifdef KTRACE 73 #include <sys/ktrace.h> 74 #endif 75 76 #include <security/audit/audit.h> 77 78 int iosize_max_clamp = 0; 79 SYSCTL_INT(_debug, OID_AUTO, iosize_max_clamp, CTLFLAG_RW, 80 &iosize_max_clamp, 0, "Clamp max i/o size to INT_MAX"); 81 int devfs_iosize_max_clamp = 1; 82 SYSCTL_INT(_debug, OID_AUTO, devfs_iosize_max_clamp, CTLFLAG_RW, 83 &devfs_iosize_max_clamp, 0, "Clamp max i/o size to INT_MAX for devices"); 84 85 /* 86 * Assert that the return value of read(2) and write(2) syscalls fits 87 * into a register. If not, an architecture will need to provide the 88 * usermode wrappers to reconstruct the result. 89 */ 90 CTASSERT(sizeof(register_t) >= sizeof(size_t)); 91 92 static MALLOC_DEFINE(M_IOCTLOPS, "ioctlops", "ioctl data buffer"); 93 static MALLOC_DEFINE(M_SELECT, "select", "select() buffer"); 94 MALLOC_DEFINE(M_IOV, "iov", "large iov's"); 95 96 static int pollout(struct thread *, struct pollfd *, struct pollfd *, 97 u_int); 98 static int pollscan(struct thread *, struct pollfd *, u_int); 99 static int pollrescan(struct thread *); 100 static int selscan(struct thread *, fd_mask **, fd_mask **, int); 101 static int selrescan(struct thread *, fd_mask **, fd_mask **); 102 static void selfdalloc(struct thread *, void *); 103 static void selfdfree(struct seltd *, struct selfd *); 104 static int dofileread(struct thread *, int, struct file *, struct uio *, 105 off_t, int); 106 static int dofilewrite(struct thread *, int, struct file *, struct uio *, 107 off_t, int); 108 static void doselwakeup(struct selinfo *, int); 109 static void seltdinit(struct thread *); 110 static int seltdwait(struct thread *, sbintime_t, sbintime_t); 111 static void seltdclear(struct thread *); 112 113 /* 114 * One seltd per-thread allocated on demand as needed. 115 * 116 * t - protected by st_mtx 117 * k - Only accessed by curthread or read-only 118 */ 119 struct seltd { 120 STAILQ_HEAD(, selfd) st_selq; /* (k) List of selfds. */ 121 struct selfd *st_free1; /* (k) free fd for read set. */ 122 struct selfd *st_free2; /* (k) free fd for write set. */ 123 struct mtx st_mtx; /* Protects struct seltd */ 124 struct cv st_wait; /* (t) Wait channel. */ 125 int st_flags; /* (t) SELTD_ flags. */ 126 }; 127 128 #define SELTD_PENDING 0x0001 /* We have pending events. */ 129 #define SELTD_RESCAN 0x0002 /* Doing a rescan. */ 130 131 /* 132 * One selfd allocated per-thread per-file-descriptor. 133 * f - protected by sf_mtx 134 */ 135 struct selfd { 136 STAILQ_ENTRY(selfd) sf_link; /* (k) fds owned by this td. */ 137 TAILQ_ENTRY(selfd) sf_threads; /* (f) fds on this selinfo. */ 138 struct selinfo *sf_si; /* (f) selinfo when linked. */ 139 struct mtx *sf_mtx; /* Pointer to selinfo mtx. */ 140 struct seltd *sf_td; /* (k) owning seltd. */ 141 void *sf_cookie; /* (k) fd or pollfd. */ 142 }; 143 144 static uma_zone_t selfd_zone; 145 static struct mtx_pool *mtxpool_select; 146 147 #ifndef _SYS_SYSPROTO_H_ 148 struct read_args { 149 int fd; 150 void *buf; 151 size_t nbyte; 152 }; 153 #endif 154 int 155 sys_read(td, uap) 156 struct thread *td; 157 struct read_args *uap; 158 { 159 struct uio auio; 160 struct iovec aiov; 161 int error; 162 163 if (uap->nbyte > IOSIZE_MAX) 164 return (EINVAL); 165 aiov.iov_base = uap->buf; 166 aiov.iov_len = uap->nbyte; 167 auio.uio_iov = &aiov; 168 auio.uio_iovcnt = 1; 169 auio.uio_resid = uap->nbyte; 170 auio.uio_segflg = UIO_USERSPACE; 171 error = kern_readv(td, uap->fd, &auio); 172 return(error); 173 } 174 175 /* 176 * Positioned read system call 177 */ 178 #ifndef _SYS_SYSPROTO_H_ 179 struct pread_args { 180 int fd; 181 void *buf; 182 size_t nbyte; 183 int pad; 184 off_t offset; 185 }; 186 #endif 187 int 188 sys_pread(td, uap) 189 struct thread *td; 190 struct pread_args *uap; 191 { 192 struct uio auio; 193 struct iovec aiov; 194 int error; 195 196 if (uap->nbyte > IOSIZE_MAX) 197 return (EINVAL); 198 aiov.iov_base = uap->buf; 199 aiov.iov_len = uap->nbyte; 200 auio.uio_iov = &aiov; 201 auio.uio_iovcnt = 1; 202 auio.uio_resid = uap->nbyte; 203 auio.uio_segflg = UIO_USERSPACE; 204 error = kern_preadv(td, uap->fd, &auio, uap->offset); 205 return(error); 206 } 207 208 int 209 freebsd6_pread(td, uap) 210 struct thread *td; 211 struct freebsd6_pread_args *uap; 212 { 213 struct pread_args oargs; 214 215 oargs.fd = uap->fd; 216 oargs.buf = uap->buf; 217 oargs.nbyte = uap->nbyte; 218 oargs.offset = uap->offset; 219 return (sys_pread(td, &oargs)); 220 } 221 222 /* 223 * Scatter read system call. 224 */ 225 #ifndef _SYS_SYSPROTO_H_ 226 struct readv_args { 227 int fd; 228 struct iovec *iovp; 229 u_int iovcnt; 230 }; 231 #endif 232 int 233 sys_readv(struct thread *td, struct readv_args *uap) 234 { 235 struct uio *auio; 236 int error; 237 238 error = copyinuio(uap->iovp, uap->iovcnt, &auio); 239 if (error) 240 return (error); 241 error = kern_readv(td, uap->fd, auio); 242 free(auio, M_IOV); 243 return (error); 244 } 245 246 int 247 kern_readv(struct thread *td, int fd, struct uio *auio) 248 { 249 struct file *fp; 250 cap_rights_t rights; 251 int error; 252 253 error = fget_read(td, fd, cap_rights_init(&rights, CAP_READ), &fp); 254 if (error) 255 return (error); 256 error = dofileread(td, fd, fp, auio, (off_t)-1, 0); 257 fdrop(fp, td); 258 return (error); 259 } 260 261 /* 262 * Scatter positioned read system call. 263 */ 264 #ifndef _SYS_SYSPROTO_H_ 265 struct preadv_args { 266 int fd; 267 struct iovec *iovp; 268 u_int iovcnt; 269 off_t offset; 270 }; 271 #endif 272 int 273 sys_preadv(struct thread *td, struct preadv_args *uap) 274 { 275 struct uio *auio; 276 int error; 277 278 error = copyinuio(uap->iovp, uap->iovcnt, &auio); 279 if (error) 280 return (error); 281 error = kern_preadv(td, uap->fd, auio, uap->offset); 282 free(auio, M_IOV); 283 return (error); 284 } 285 286 int 287 kern_preadv(td, fd, auio, offset) 288 struct thread *td; 289 int fd; 290 struct uio *auio; 291 off_t offset; 292 { 293 struct file *fp; 294 cap_rights_t rights; 295 int error; 296 297 error = fget_read(td, fd, cap_rights_init(&rights, CAP_PREAD), &fp); 298 if (error) 299 return (error); 300 if (!(fp->f_ops->fo_flags & DFLAG_SEEKABLE)) 301 error = ESPIPE; 302 else if (offset < 0 && fp->f_vnode->v_type != VCHR) 303 error = EINVAL; 304 else 305 error = dofileread(td, fd, fp, auio, offset, FOF_OFFSET); 306 fdrop(fp, td); 307 return (error); 308 } 309 310 /* 311 * Common code for readv and preadv that reads data in 312 * from a file using the passed in uio, offset, and flags. 313 */ 314 static int 315 dofileread(td, fd, fp, auio, offset, flags) 316 struct thread *td; 317 int fd; 318 struct file *fp; 319 struct uio *auio; 320 off_t offset; 321 int flags; 322 { 323 ssize_t cnt; 324 int error; 325 #ifdef KTRACE 326 struct uio *ktruio = NULL; 327 #endif 328 329 /* Finish zero length reads right here */ 330 if (auio->uio_resid == 0) { 331 td->td_retval[0] = 0; 332 return(0); 333 } 334 auio->uio_rw = UIO_READ; 335 auio->uio_offset = offset; 336 auio->uio_td = td; 337 #ifdef KTRACE 338 if (KTRPOINT(td, KTR_GENIO)) 339 ktruio = cloneuio(auio); 340 #endif 341 cnt = auio->uio_resid; 342 if ((error = fo_read(fp, auio, td->td_ucred, flags, td))) { 343 if (auio->uio_resid != cnt && (error == ERESTART || 344 error == EINTR || error == EWOULDBLOCK)) 345 error = 0; 346 } 347 cnt -= auio->uio_resid; 348 #ifdef KTRACE 349 if (ktruio != NULL) { 350 ktruio->uio_resid = cnt; 351 ktrgenio(fd, UIO_READ, ktruio, error); 352 } 353 #endif 354 td->td_retval[0] = cnt; 355 return (error); 356 } 357 358 #ifndef _SYS_SYSPROTO_H_ 359 struct write_args { 360 int fd; 361 const void *buf; 362 size_t nbyte; 363 }; 364 #endif 365 int 366 sys_write(td, uap) 367 struct thread *td; 368 struct write_args *uap; 369 { 370 struct uio auio; 371 struct iovec aiov; 372 int error; 373 374 if (uap->nbyte > IOSIZE_MAX) 375 return (EINVAL); 376 aiov.iov_base = (void *)(uintptr_t)uap->buf; 377 aiov.iov_len = uap->nbyte; 378 auio.uio_iov = &aiov; 379 auio.uio_iovcnt = 1; 380 auio.uio_resid = uap->nbyte; 381 auio.uio_segflg = UIO_USERSPACE; 382 error = kern_writev(td, uap->fd, &auio); 383 return(error); 384 } 385 386 /* 387 * Positioned write system call. 388 */ 389 #ifndef _SYS_SYSPROTO_H_ 390 struct pwrite_args { 391 int fd; 392 const void *buf; 393 size_t nbyte; 394 int pad; 395 off_t offset; 396 }; 397 #endif 398 int 399 sys_pwrite(td, uap) 400 struct thread *td; 401 struct pwrite_args *uap; 402 { 403 struct uio auio; 404 struct iovec aiov; 405 int error; 406 407 if (uap->nbyte > IOSIZE_MAX) 408 return (EINVAL); 409 aiov.iov_base = (void *)(uintptr_t)uap->buf; 410 aiov.iov_len = uap->nbyte; 411 auio.uio_iov = &aiov; 412 auio.uio_iovcnt = 1; 413 auio.uio_resid = uap->nbyte; 414 auio.uio_segflg = UIO_USERSPACE; 415 error = kern_pwritev(td, uap->fd, &auio, uap->offset); 416 return(error); 417 } 418 419 int 420 freebsd6_pwrite(td, uap) 421 struct thread *td; 422 struct freebsd6_pwrite_args *uap; 423 { 424 struct pwrite_args oargs; 425 426 oargs.fd = uap->fd; 427 oargs.buf = uap->buf; 428 oargs.nbyte = uap->nbyte; 429 oargs.offset = uap->offset; 430 return (sys_pwrite(td, &oargs)); 431 } 432 433 /* 434 * Gather write system call. 435 */ 436 #ifndef _SYS_SYSPROTO_H_ 437 struct writev_args { 438 int fd; 439 struct iovec *iovp; 440 u_int iovcnt; 441 }; 442 #endif 443 int 444 sys_writev(struct thread *td, struct writev_args *uap) 445 { 446 struct uio *auio; 447 int error; 448 449 error = copyinuio(uap->iovp, uap->iovcnt, &auio); 450 if (error) 451 return (error); 452 error = kern_writev(td, uap->fd, auio); 453 free(auio, M_IOV); 454 return (error); 455 } 456 457 int 458 kern_writev(struct thread *td, int fd, struct uio *auio) 459 { 460 struct file *fp; 461 cap_rights_t rights; 462 int error; 463 464 error = fget_write(td, fd, cap_rights_init(&rights, CAP_WRITE), &fp); 465 if (error) 466 return (error); 467 error = dofilewrite(td, fd, fp, auio, (off_t)-1, 0); 468 fdrop(fp, td); 469 return (error); 470 } 471 472 /* 473 * Gather positioned write system call. 474 */ 475 #ifndef _SYS_SYSPROTO_H_ 476 struct pwritev_args { 477 int fd; 478 struct iovec *iovp; 479 u_int iovcnt; 480 off_t offset; 481 }; 482 #endif 483 int 484 sys_pwritev(struct thread *td, struct pwritev_args *uap) 485 { 486 struct uio *auio; 487 int error; 488 489 error = copyinuio(uap->iovp, uap->iovcnt, &auio); 490 if (error) 491 return (error); 492 error = kern_pwritev(td, uap->fd, auio, uap->offset); 493 free(auio, M_IOV); 494 return (error); 495 } 496 497 int 498 kern_pwritev(td, fd, auio, offset) 499 struct thread *td; 500 struct uio *auio; 501 int fd; 502 off_t offset; 503 { 504 struct file *fp; 505 cap_rights_t rights; 506 int error; 507 508 error = fget_write(td, fd, cap_rights_init(&rights, CAP_PWRITE), &fp); 509 if (error) 510 return (error); 511 if (!(fp->f_ops->fo_flags & DFLAG_SEEKABLE)) 512 error = ESPIPE; 513 else if (offset < 0 && fp->f_vnode->v_type != VCHR) 514 error = EINVAL; 515 else 516 error = dofilewrite(td, fd, fp, auio, offset, FOF_OFFSET); 517 fdrop(fp, td); 518 return (error); 519 } 520 521 /* 522 * Common code for writev and pwritev that writes data to 523 * a file using the passed in uio, offset, and flags. 524 */ 525 static int 526 dofilewrite(td, fd, fp, auio, offset, flags) 527 struct thread *td; 528 int fd; 529 struct file *fp; 530 struct uio *auio; 531 off_t offset; 532 int flags; 533 { 534 ssize_t cnt; 535 int error; 536 #ifdef KTRACE 537 struct uio *ktruio = NULL; 538 #endif 539 540 auio->uio_rw = UIO_WRITE; 541 auio->uio_td = td; 542 auio->uio_offset = offset; 543 #ifdef KTRACE 544 if (KTRPOINT(td, KTR_GENIO)) 545 ktruio = cloneuio(auio); 546 #endif 547 cnt = auio->uio_resid; 548 if (fp->f_type == DTYPE_VNODE && 549 (fp->f_vnread_flags & FDEVFS_VNODE) == 0) 550 bwillwrite(); 551 if ((error = fo_write(fp, auio, td->td_ucred, flags, td))) { 552 if (auio->uio_resid != cnt && (error == ERESTART || 553 error == EINTR || error == EWOULDBLOCK)) 554 error = 0; 555 /* Socket layer is responsible for issuing SIGPIPE. */ 556 if (fp->f_type != DTYPE_SOCKET && error == EPIPE) { 557 PROC_LOCK(td->td_proc); 558 tdsignal(td, SIGPIPE); 559 PROC_UNLOCK(td->td_proc); 560 } 561 } 562 cnt -= auio->uio_resid; 563 #ifdef KTRACE 564 if (ktruio != NULL) { 565 ktruio->uio_resid = cnt; 566 ktrgenio(fd, UIO_WRITE, ktruio, error); 567 } 568 #endif 569 td->td_retval[0] = cnt; 570 return (error); 571 } 572 573 /* 574 * Truncate a file given a file descriptor. 575 * 576 * Can't use fget_write() here, since must return EINVAL and not EBADF if the 577 * descriptor isn't writable. 578 */ 579 int 580 kern_ftruncate(td, fd, length) 581 struct thread *td; 582 int fd; 583 off_t length; 584 { 585 struct file *fp; 586 cap_rights_t rights; 587 int error; 588 589 AUDIT_ARG_FD(fd); 590 if (length < 0) 591 return (EINVAL); 592 error = fget(td, fd, cap_rights_init(&rights, CAP_FTRUNCATE), &fp); 593 if (error) 594 return (error); 595 AUDIT_ARG_FILE(td->td_proc, fp); 596 if (!(fp->f_flag & FWRITE)) { 597 fdrop(fp, td); 598 return (EINVAL); 599 } 600 error = fo_truncate(fp, length, td->td_ucred, td); 601 fdrop(fp, td); 602 return (error); 603 } 604 605 #ifndef _SYS_SYSPROTO_H_ 606 struct ftruncate_args { 607 int fd; 608 int pad; 609 off_t length; 610 }; 611 #endif 612 int 613 sys_ftruncate(td, uap) 614 struct thread *td; 615 struct ftruncate_args *uap; 616 { 617 618 return (kern_ftruncate(td, uap->fd, uap->length)); 619 } 620 621 #if defined(COMPAT_43) 622 #ifndef _SYS_SYSPROTO_H_ 623 struct oftruncate_args { 624 int fd; 625 long length; 626 }; 627 #endif 628 int 629 oftruncate(td, uap) 630 struct thread *td; 631 struct oftruncate_args *uap; 632 { 633 634 return (kern_ftruncate(td, uap->fd, uap->length)); 635 } 636 #endif /* COMPAT_43 */ 637 638 #ifndef _SYS_SYSPROTO_H_ 639 struct ioctl_args { 640 int fd; 641 u_long com; 642 caddr_t data; 643 }; 644 #endif 645 /* ARGSUSED */ 646 int 647 sys_ioctl(struct thread *td, struct ioctl_args *uap) 648 { 649 #ifndef SYS_IOCTL_SMALL_SIZE 650 #define SYS_IOCTL_SMALL_SIZE 128 651 #endif 652 u_char smalldata[SYS_IOCTL_SMALL_SIZE] __aligned(8); 653 u_long com; 654 int arg, error; 655 u_int size; 656 caddr_t data; 657 658 if (uap->com > 0xffffffff) { 659 printf( 660 "WARNING pid %d (%s): ioctl sign-extension ioctl %lx\n", 661 td->td_proc->p_pid, td->td_name, uap->com); 662 uap->com &= 0xffffffff; 663 } 664 com = uap->com; 665 666 /* 667 * Interpret high order word to find amount of data to be 668 * copied to/from the user's address space. 669 */ 670 size = IOCPARM_LEN(com); 671 if ((size > IOCPARM_MAX) || 672 ((com & (IOC_VOID | IOC_IN | IOC_OUT)) == 0) || 673 #if defined(COMPAT_FREEBSD5) || defined(COMPAT_FREEBSD4) || defined(COMPAT_43) 674 ((com & IOC_OUT) && size == 0) || 675 #else 676 ((com & (IOC_IN | IOC_OUT)) && size == 0) || 677 #endif 678 ((com & IOC_VOID) && size > 0 && size != sizeof(int))) 679 return (ENOTTY); 680 681 if (size > 0) { 682 if (com & IOC_VOID) { 683 /* Integer argument. */ 684 arg = (intptr_t)uap->data; 685 data = (void *)&arg; 686 size = 0; 687 } else { 688 if (size > SYS_IOCTL_SMALL_SIZE) 689 data = malloc((u_long)size, M_IOCTLOPS, M_WAITOK); 690 else 691 data = smalldata; 692 } 693 } else 694 data = (void *)&uap->data; 695 if (com & IOC_IN) { 696 error = copyin(uap->data, data, (u_int)size); 697 if (error != 0) 698 goto out; 699 } else if (com & IOC_OUT) { 700 /* 701 * Zero the buffer so the user always 702 * gets back something deterministic. 703 */ 704 bzero(data, size); 705 } 706 707 error = kern_ioctl(td, uap->fd, com, data); 708 709 if (error == 0 && (com & IOC_OUT)) 710 error = copyout(data, uap->data, (u_int)size); 711 712 out: 713 if (size > SYS_IOCTL_SMALL_SIZE) 714 free(data, M_IOCTLOPS); 715 return (error); 716 } 717 718 int 719 kern_ioctl(struct thread *td, int fd, u_long com, caddr_t data) 720 { 721 struct file *fp; 722 struct filedesc *fdp; 723 #ifndef CAPABILITIES 724 cap_rights_t rights; 725 #endif 726 int error, tmp, locked; 727 728 AUDIT_ARG_FD(fd); 729 AUDIT_ARG_CMD(com); 730 731 fdp = td->td_proc->p_fd; 732 733 switch (com) { 734 case FIONCLEX: 735 case FIOCLEX: 736 FILEDESC_XLOCK(fdp); 737 locked = LA_XLOCKED; 738 break; 739 default: 740 #ifdef CAPABILITIES 741 FILEDESC_SLOCK(fdp); 742 locked = LA_SLOCKED; 743 #else 744 locked = LA_UNLOCKED; 745 #endif 746 break; 747 } 748 749 #ifdef CAPABILITIES 750 if ((fp = fget_locked(fdp, fd)) == NULL) { 751 error = EBADF; 752 goto out; 753 } 754 if ((error = cap_ioctl_check(fdp, fd, com)) != 0) { 755 fp = NULL; /* fhold() was not called yet */ 756 goto out; 757 } 758 fhold(fp); 759 if (locked == LA_SLOCKED) { 760 FILEDESC_SUNLOCK(fdp); 761 locked = LA_UNLOCKED; 762 } 763 #else 764 error = fget(td, fd, cap_rights_init(&rights, CAP_IOCTL), &fp); 765 if (error != 0) { 766 fp = NULL; 767 goto out; 768 } 769 #endif 770 if ((fp->f_flag & (FREAD | FWRITE)) == 0) { 771 error = EBADF; 772 goto out; 773 } 774 775 switch (com) { 776 case FIONCLEX: 777 fdp->fd_ofiles[fd].fde_flags &= ~UF_EXCLOSE; 778 goto out; 779 case FIOCLEX: 780 fdp->fd_ofiles[fd].fde_flags |= UF_EXCLOSE; 781 goto out; 782 case FIONBIO: 783 if ((tmp = *(int *)data)) 784 atomic_set_int(&fp->f_flag, FNONBLOCK); 785 else 786 atomic_clear_int(&fp->f_flag, FNONBLOCK); 787 data = (void *)&tmp; 788 break; 789 case FIOASYNC: 790 if ((tmp = *(int *)data)) 791 atomic_set_int(&fp->f_flag, FASYNC); 792 else 793 atomic_clear_int(&fp->f_flag, FASYNC); 794 data = (void *)&tmp; 795 break; 796 } 797 798 error = fo_ioctl(fp, com, data, td->td_ucred, td); 799 out: 800 switch (locked) { 801 case LA_XLOCKED: 802 FILEDESC_XUNLOCK(fdp); 803 break; 804 #ifdef CAPABILITIES 805 case LA_SLOCKED: 806 FILEDESC_SUNLOCK(fdp); 807 break; 808 #endif 809 default: 810 FILEDESC_UNLOCK_ASSERT(fdp); 811 break; 812 } 813 if (fp != NULL) 814 fdrop(fp, td); 815 return (error); 816 } 817 818 int 819 poll_no_poll(int events) 820 { 821 /* 822 * Return true for read/write. If the user asked for something 823 * special, return POLLNVAL, so that clients have a way of 824 * determining reliably whether or not the extended 825 * functionality is present without hard-coding knowledge 826 * of specific filesystem implementations. 827 */ 828 if (events & ~POLLSTANDARD) 829 return (POLLNVAL); 830 831 return (events & (POLLIN | POLLOUT | POLLRDNORM | POLLWRNORM)); 832 } 833 834 int 835 sys_pselect(struct thread *td, struct pselect_args *uap) 836 { 837 struct timespec ts; 838 struct timeval tv, *tvp; 839 sigset_t set, *uset; 840 int error; 841 842 if (uap->ts != NULL) { 843 error = copyin(uap->ts, &ts, sizeof(ts)); 844 if (error != 0) 845 return (error); 846 TIMESPEC_TO_TIMEVAL(&tv, &ts); 847 tvp = &tv; 848 } else 849 tvp = NULL; 850 if (uap->sm != NULL) { 851 error = copyin(uap->sm, &set, sizeof(set)); 852 if (error != 0) 853 return (error); 854 uset = &set; 855 } else 856 uset = NULL; 857 return (kern_pselect(td, uap->nd, uap->in, uap->ou, uap->ex, tvp, 858 uset, NFDBITS)); 859 } 860 861 int 862 kern_pselect(struct thread *td, int nd, fd_set *in, fd_set *ou, fd_set *ex, 863 struct timeval *tvp, sigset_t *uset, int abi_nfdbits) 864 { 865 int error; 866 867 if (uset != NULL) { 868 error = kern_sigprocmask(td, SIG_SETMASK, uset, 869 &td->td_oldsigmask, 0); 870 if (error != 0) 871 return (error); 872 td->td_pflags |= TDP_OLDMASK; 873 /* 874 * Make sure that ast() is called on return to 875 * usermode and TDP_OLDMASK is cleared, restoring old 876 * sigmask. 877 */ 878 thread_lock(td); 879 td->td_flags |= TDF_ASTPENDING; 880 thread_unlock(td); 881 } 882 error = kern_select(td, nd, in, ou, ex, tvp, abi_nfdbits); 883 return (error); 884 } 885 886 #ifndef _SYS_SYSPROTO_H_ 887 struct select_args { 888 int nd; 889 fd_set *in, *ou, *ex; 890 struct timeval *tv; 891 }; 892 #endif 893 int 894 sys_select(struct thread *td, struct select_args *uap) 895 { 896 struct timeval tv, *tvp; 897 int error; 898 899 if (uap->tv != NULL) { 900 error = copyin(uap->tv, &tv, sizeof(tv)); 901 if (error) 902 return (error); 903 tvp = &tv; 904 } else 905 tvp = NULL; 906 907 return (kern_select(td, uap->nd, uap->in, uap->ou, uap->ex, tvp, 908 NFDBITS)); 909 } 910 911 /* 912 * In the unlikely case when user specified n greater then the last 913 * open file descriptor, check that no bits are set after the last 914 * valid fd. We must return EBADF if any is set. 915 * 916 * There are applications that rely on the behaviour. 917 * 918 * nd is fd_lastfile + 1. 919 */ 920 static int 921 select_check_badfd(fd_set *fd_in, int nd, int ndu, int abi_nfdbits) 922 { 923 char *addr, *oaddr; 924 int b, i, res; 925 uint8_t bits; 926 927 if (nd >= ndu || fd_in == NULL) 928 return (0); 929 930 oaddr = NULL; 931 bits = 0; /* silence gcc */ 932 for (i = nd; i < ndu; i++) { 933 b = i / NBBY; 934 #if BYTE_ORDER == LITTLE_ENDIAN 935 addr = (char *)fd_in + b; 936 #else 937 addr = (char *)fd_in; 938 if (abi_nfdbits == NFDBITS) { 939 addr += rounddown(b, sizeof(fd_mask)) + 940 sizeof(fd_mask) - 1 - b % sizeof(fd_mask); 941 } else { 942 addr += rounddown(b, sizeof(uint32_t)) + 943 sizeof(uint32_t) - 1 - b % sizeof(uint32_t); 944 } 945 #endif 946 if (addr != oaddr) { 947 res = fubyte(addr); 948 if (res == -1) 949 return (EFAULT); 950 oaddr = addr; 951 bits = res; 952 } 953 if ((bits & (1 << (i % NBBY))) != 0) 954 return (EBADF); 955 } 956 return (0); 957 } 958 959 int 960 kern_select(struct thread *td, int nd, fd_set *fd_in, fd_set *fd_ou, 961 fd_set *fd_ex, struct timeval *tvp, int abi_nfdbits) 962 { 963 struct filedesc *fdp; 964 /* 965 * The magic 2048 here is chosen to be just enough for FD_SETSIZE 966 * infds with the new FD_SETSIZE of 1024, and more than enough for 967 * FD_SETSIZE infds, outfds and exceptfds with the old FD_SETSIZE 968 * of 256. 969 */ 970 fd_mask s_selbits[howmany(2048, NFDBITS)]; 971 fd_mask *ibits[3], *obits[3], *selbits, *sbp; 972 struct timeval rtv; 973 sbintime_t asbt, precision, rsbt; 974 u_int nbufbytes, ncpbytes, ncpubytes, nfdbits; 975 int error, lf, ndu; 976 977 if (nd < 0) 978 return (EINVAL); 979 fdp = td->td_proc->p_fd; 980 ndu = nd; 981 lf = fdp->fd_lastfile; 982 if (nd > lf + 1) 983 nd = lf + 1; 984 985 error = select_check_badfd(fd_in, nd, ndu, abi_nfdbits); 986 if (error != 0) 987 return (error); 988 error = select_check_badfd(fd_ou, nd, ndu, abi_nfdbits); 989 if (error != 0) 990 return (error); 991 error = select_check_badfd(fd_ex, nd, ndu, abi_nfdbits); 992 if (error != 0) 993 return (error); 994 995 /* 996 * Allocate just enough bits for the non-null fd_sets. Use the 997 * preallocated auto buffer if possible. 998 */ 999 nfdbits = roundup(nd, NFDBITS); 1000 ncpbytes = nfdbits / NBBY; 1001 ncpubytes = roundup(nd, abi_nfdbits) / NBBY; 1002 nbufbytes = 0; 1003 if (fd_in != NULL) 1004 nbufbytes += 2 * ncpbytes; 1005 if (fd_ou != NULL) 1006 nbufbytes += 2 * ncpbytes; 1007 if (fd_ex != NULL) 1008 nbufbytes += 2 * ncpbytes; 1009 if (nbufbytes <= sizeof s_selbits) 1010 selbits = &s_selbits[0]; 1011 else 1012 selbits = malloc(nbufbytes, M_SELECT, M_WAITOK); 1013 1014 /* 1015 * Assign pointers into the bit buffers and fetch the input bits. 1016 * Put the output buffers together so that they can be bzeroed 1017 * together. 1018 */ 1019 sbp = selbits; 1020 #define getbits(name, x) \ 1021 do { \ 1022 if (name == NULL) { \ 1023 ibits[x] = NULL; \ 1024 obits[x] = NULL; \ 1025 } else { \ 1026 ibits[x] = sbp + nbufbytes / 2 / sizeof *sbp; \ 1027 obits[x] = sbp; \ 1028 sbp += ncpbytes / sizeof *sbp; \ 1029 error = copyin(name, ibits[x], ncpubytes); \ 1030 if (error != 0) \ 1031 goto done; \ 1032 bzero((char *)ibits[x] + ncpubytes, \ 1033 ncpbytes - ncpubytes); \ 1034 } \ 1035 } while (0) 1036 getbits(fd_in, 0); 1037 getbits(fd_ou, 1); 1038 getbits(fd_ex, 2); 1039 #undef getbits 1040 1041 #if BYTE_ORDER == BIG_ENDIAN && defined(__LP64__) 1042 /* 1043 * XXX: swizzle_fdset assumes that if abi_nfdbits != NFDBITS, 1044 * we are running under 32-bit emulation. This should be more 1045 * generic. 1046 */ 1047 #define swizzle_fdset(bits) \ 1048 if (abi_nfdbits != NFDBITS && bits != NULL) { \ 1049 int i; \ 1050 for (i = 0; i < ncpbytes / sizeof *sbp; i++) \ 1051 bits[i] = (bits[i] >> 32) | (bits[i] << 32); \ 1052 } 1053 #else 1054 #define swizzle_fdset(bits) 1055 #endif 1056 1057 /* Make sure the bit order makes it through an ABI transition */ 1058 swizzle_fdset(ibits[0]); 1059 swizzle_fdset(ibits[1]); 1060 swizzle_fdset(ibits[2]); 1061 1062 if (nbufbytes != 0) 1063 bzero(selbits, nbufbytes / 2); 1064 1065 precision = 0; 1066 if (tvp != NULL) { 1067 rtv = *tvp; 1068 if (rtv.tv_sec < 0 || rtv.tv_usec < 0 || 1069 rtv.tv_usec >= 1000000) { 1070 error = EINVAL; 1071 goto done; 1072 } 1073 if (!timevalisset(&rtv)) 1074 asbt = 0; 1075 else if (rtv.tv_sec <= INT32_MAX) { 1076 rsbt = tvtosbt(rtv); 1077 precision = rsbt; 1078 precision >>= tc_precexp; 1079 if (TIMESEL(&asbt, rsbt)) 1080 asbt += tc_tick_sbt; 1081 if (asbt <= SBT_MAX - rsbt) 1082 asbt += rsbt; 1083 else 1084 asbt = -1; 1085 } else 1086 asbt = -1; 1087 } else 1088 asbt = -1; 1089 seltdinit(td); 1090 /* Iterate until the timeout expires or descriptors become ready. */ 1091 for (;;) { 1092 error = selscan(td, ibits, obits, nd); 1093 if (error || td->td_retval[0] != 0) 1094 break; 1095 error = seltdwait(td, asbt, precision); 1096 if (error) 1097 break; 1098 error = selrescan(td, ibits, obits); 1099 if (error || td->td_retval[0] != 0) 1100 break; 1101 } 1102 seltdclear(td); 1103 1104 done: 1105 /* select is not restarted after signals... */ 1106 if (error == ERESTART) 1107 error = EINTR; 1108 if (error == EWOULDBLOCK) 1109 error = 0; 1110 1111 /* swizzle bit order back, if necessary */ 1112 swizzle_fdset(obits[0]); 1113 swizzle_fdset(obits[1]); 1114 swizzle_fdset(obits[2]); 1115 #undef swizzle_fdset 1116 1117 #define putbits(name, x) \ 1118 if (name && (error2 = copyout(obits[x], name, ncpubytes))) \ 1119 error = error2; 1120 if (error == 0) { 1121 int error2; 1122 1123 putbits(fd_in, 0); 1124 putbits(fd_ou, 1); 1125 putbits(fd_ex, 2); 1126 #undef putbits 1127 } 1128 if (selbits != &s_selbits[0]) 1129 free(selbits, M_SELECT); 1130 1131 return (error); 1132 } 1133 /* 1134 * Convert a select bit set to poll flags. 1135 * 1136 * The backend always returns POLLHUP/POLLERR if appropriate and we 1137 * return this as a set bit in any set. 1138 */ 1139 static int select_flags[3] = { 1140 POLLRDNORM | POLLHUP | POLLERR, 1141 POLLWRNORM | POLLHUP | POLLERR, 1142 POLLRDBAND | POLLERR 1143 }; 1144 1145 /* 1146 * Compute the fo_poll flags required for a fd given by the index and 1147 * bit position in the fd_mask array. 1148 */ 1149 static __inline int 1150 selflags(fd_mask **ibits, int idx, fd_mask bit) 1151 { 1152 int flags; 1153 int msk; 1154 1155 flags = 0; 1156 for (msk = 0; msk < 3; msk++) { 1157 if (ibits[msk] == NULL) 1158 continue; 1159 if ((ibits[msk][idx] & bit) == 0) 1160 continue; 1161 flags |= select_flags[msk]; 1162 } 1163 return (flags); 1164 } 1165 1166 /* 1167 * Set the appropriate output bits given a mask of fired events and the 1168 * input bits originally requested. 1169 */ 1170 static __inline int 1171 selsetbits(fd_mask **ibits, fd_mask **obits, int idx, fd_mask bit, int events) 1172 { 1173 int msk; 1174 int n; 1175 1176 n = 0; 1177 for (msk = 0; msk < 3; msk++) { 1178 if ((events & select_flags[msk]) == 0) 1179 continue; 1180 if (ibits[msk] == NULL) 1181 continue; 1182 if ((ibits[msk][idx] & bit) == 0) 1183 continue; 1184 /* 1185 * XXX Check for a duplicate set. This can occur because a 1186 * socket calls selrecord() twice for each poll() call 1187 * resulting in two selfds per real fd. selrescan() will 1188 * call selsetbits twice as a result. 1189 */ 1190 if ((obits[msk][idx] & bit) != 0) 1191 continue; 1192 obits[msk][idx] |= bit; 1193 n++; 1194 } 1195 1196 return (n); 1197 } 1198 1199 static __inline int 1200 getselfd_cap(struct filedesc *fdp, int fd, struct file **fpp) 1201 { 1202 cap_rights_t rights; 1203 1204 cap_rights_init(&rights, CAP_EVENT); 1205 1206 return (fget_unlocked(fdp, fd, &rights, 0, fpp, NULL)); 1207 } 1208 1209 /* 1210 * Traverse the list of fds attached to this thread's seltd and check for 1211 * completion. 1212 */ 1213 static int 1214 selrescan(struct thread *td, fd_mask **ibits, fd_mask **obits) 1215 { 1216 struct filedesc *fdp; 1217 struct selinfo *si; 1218 struct seltd *stp; 1219 struct selfd *sfp; 1220 struct selfd *sfn; 1221 struct file *fp; 1222 fd_mask bit; 1223 int fd, ev, n, idx; 1224 int error; 1225 1226 fdp = td->td_proc->p_fd; 1227 stp = td->td_sel; 1228 n = 0; 1229 STAILQ_FOREACH_SAFE(sfp, &stp->st_selq, sf_link, sfn) { 1230 fd = (int)(uintptr_t)sfp->sf_cookie; 1231 si = sfp->sf_si; 1232 selfdfree(stp, sfp); 1233 /* If the selinfo wasn't cleared the event didn't fire. */ 1234 if (si != NULL) 1235 continue; 1236 error = getselfd_cap(fdp, fd, &fp); 1237 if (error) 1238 return (error); 1239 idx = fd / NFDBITS; 1240 bit = (fd_mask)1 << (fd % NFDBITS); 1241 ev = fo_poll(fp, selflags(ibits, idx, bit), td->td_ucred, td); 1242 fdrop(fp, td); 1243 if (ev != 0) 1244 n += selsetbits(ibits, obits, idx, bit, ev); 1245 } 1246 stp->st_flags = 0; 1247 td->td_retval[0] = n; 1248 return (0); 1249 } 1250 1251 /* 1252 * Perform the initial filedescriptor scan and register ourselves with 1253 * each selinfo. 1254 */ 1255 static int 1256 selscan(td, ibits, obits, nfd) 1257 struct thread *td; 1258 fd_mask **ibits, **obits; 1259 int nfd; 1260 { 1261 struct filedesc *fdp; 1262 struct file *fp; 1263 fd_mask bit; 1264 int ev, flags, end, fd; 1265 int n, idx; 1266 int error; 1267 1268 fdp = td->td_proc->p_fd; 1269 n = 0; 1270 for (idx = 0, fd = 0; fd < nfd; idx++) { 1271 end = imin(fd + NFDBITS, nfd); 1272 for (bit = 1; fd < end; bit <<= 1, fd++) { 1273 /* Compute the list of events we're interested in. */ 1274 flags = selflags(ibits, idx, bit); 1275 if (flags == 0) 1276 continue; 1277 error = getselfd_cap(fdp, fd, &fp); 1278 if (error) 1279 return (error); 1280 selfdalloc(td, (void *)(uintptr_t)fd); 1281 ev = fo_poll(fp, flags, td->td_ucred, td); 1282 fdrop(fp, td); 1283 if (ev != 0) 1284 n += selsetbits(ibits, obits, idx, bit, ev); 1285 } 1286 } 1287 1288 td->td_retval[0] = n; 1289 return (0); 1290 } 1291 1292 int 1293 sys_poll(struct thread *td, struct poll_args *uap) 1294 { 1295 struct timespec ts, *tsp; 1296 1297 if (uap->timeout != INFTIM) { 1298 if (uap->timeout < 0) 1299 return (EINVAL); 1300 ts.tv_sec = uap->timeout / 1000; 1301 ts.tv_nsec = (uap->timeout % 1000) * 1000000; 1302 tsp = &ts; 1303 } else 1304 tsp = NULL; 1305 1306 return (kern_poll(td, uap->fds, uap->nfds, tsp, NULL)); 1307 } 1308 1309 int 1310 kern_poll(struct thread *td, struct pollfd *fds, u_int nfds, 1311 struct timespec *tsp, sigset_t *uset) 1312 { 1313 struct pollfd *bits; 1314 struct pollfd smallbits[32]; 1315 sbintime_t sbt, precision, tmp; 1316 time_t over; 1317 struct timespec ts; 1318 int error; 1319 size_t ni; 1320 1321 precision = 0; 1322 if (tsp != NULL) { 1323 if (tsp->tv_sec < 0) 1324 return (EINVAL); 1325 if (tsp->tv_nsec < 0 || tsp->tv_nsec >= 1000000000) 1326 return (EINVAL); 1327 if (tsp->tv_sec == 0 && tsp->tv_nsec == 0) 1328 sbt = 0; 1329 else { 1330 ts = *tsp; 1331 if (ts.tv_sec > INT32_MAX / 2) { 1332 over = ts.tv_sec - INT32_MAX / 2; 1333 ts.tv_sec -= over; 1334 } else 1335 over = 0; 1336 tmp = tstosbt(ts); 1337 precision = tmp; 1338 precision >>= tc_precexp; 1339 if (TIMESEL(&sbt, tmp)) 1340 sbt += tc_tick_sbt; 1341 sbt += tmp; 1342 } 1343 } else 1344 sbt = -1; 1345 1346 if (nfds > maxfilesperproc && nfds > FD_SETSIZE) 1347 return (EINVAL); 1348 ni = nfds * sizeof(struct pollfd); 1349 if (ni > sizeof(smallbits)) 1350 bits = malloc(ni, M_TEMP, M_WAITOK); 1351 else 1352 bits = smallbits; 1353 error = copyin(fds, bits, ni); 1354 if (error) 1355 goto done; 1356 1357 if (uset != NULL) { 1358 error = kern_sigprocmask(td, SIG_SETMASK, uset, 1359 &td->td_oldsigmask, 0); 1360 if (error) 1361 goto done; 1362 td->td_pflags |= TDP_OLDMASK; 1363 /* 1364 * Make sure that ast() is called on return to 1365 * usermode and TDP_OLDMASK is cleared, restoring old 1366 * sigmask. 1367 */ 1368 thread_lock(td); 1369 td->td_flags |= TDF_ASTPENDING; 1370 thread_unlock(td); 1371 } 1372 1373 seltdinit(td); 1374 /* Iterate until the timeout expires or descriptors become ready. */ 1375 for (;;) { 1376 error = pollscan(td, bits, nfds); 1377 if (error || td->td_retval[0] != 0) 1378 break; 1379 error = seltdwait(td, sbt, precision); 1380 if (error) 1381 break; 1382 error = pollrescan(td); 1383 if (error || td->td_retval[0] != 0) 1384 break; 1385 } 1386 seltdclear(td); 1387 1388 done: 1389 /* poll is not restarted after signals... */ 1390 if (error == ERESTART) 1391 error = EINTR; 1392 if (error == EWOULDBLOCK) 1393 error = 0; 1394 if (error == 0) { 1395 error = pollout(td, bits, fds, nfds); 1396 if (error) 1397 goto out; 1398 } 1399 out: 1400 if (ni > sizeof(smallbits)) 1401 free(bits, M_TEMP); 1402 return (error); 1403 } 1404 1405 int 1406 sys_ppoll(struct thread *td, struct ppoll_args *uap) 1407 { 1408 struct timespec ts, *tsp; 1409 sigset_t set, *ssp; 1410 int error; 1411 1412 if (uap->ts != NULL) { 1413 error = copyin(uap->ts, &ts, sizeof(ts)); 1414 if (error) 1415 return (error); 1416 tsp = &ts; 1417 } else 1418 tsp = NULL; 1419 if (uap->set != NULL) { 1420 error = copyin(uap->set, &set, sizeof(set)); 1421 if (error) 1422 return (error); 1423 ssp = &set; 1424 } else 1425 ssp = NULL; 1426 /* 1427 * fds is still a pointer to user space. kern_poll() will 1428 * take care of copyin that array to the kernel space. 1429 */ 1430 1431 return (kern_poll(td, uap->fds, uap->nfds, tsp, ssp)); 1432 } 1433 1434 static int 1435 pollrescan(struct thread *td) 1436 { 1437 struct seltd *stp; 1438 struct selfd *sfp; 1439 struct selfd *sfn; 1440 struct selinfo *si; 1441 struct filedesc *fdp; 1442 struct file *fp; 1443 struct pollfd *fd; 1444 #ifdef CAPABILITIES 1445 cap_rights_t rights; 1446 #endif 1447 int n; 1448 1449 n = 0; 1450 fdp = td->td_proc->p_fd; 1451 stp = td->td_sel; 1452 FILEDESC_SLOCK(fdp); 1453 STAILQ_FOREACH_SAFE(sfp, &stp->st_selq, sf_link, sfn) { 1454 fd = (struct pollfd *)sfp->sf_cookie; 1455 si = sfp->sf_si; 1456 selfdfree(stp, sfp); 1457 /* If the selinfo wasn't cleared the event didn't fire. */ 1458 if (si != NULL) 1459 continue; 1460 fp = fdp->fd_ofiles[fd->fd].fde_file; 1461 #ifdef CAPABILITIES 1462 if (fp == NULL || 1463 cap_check(cap_rights(fdp, fd->fd), 1464 cap_rights_init(&rights, CAP_EVENT)) != 0) 1465 #else 1466 if (fp == NULL) 1467 #endif 1468 { 1469 fd->revents = POLLNVAL; 1470 n++; 1471 continue; 1472 } 1473 1474 /* 1475 * Note: backend also returns POLLHUP and 1476 * POLLERR if appropriate. 1477 */ 1478 fd->revents = fo_poll(fp, fd->events, td->td_ucred, td); 1479 if (fd->revents != 0) 1480 n++; 1481 } 1482 FILEDESC_SUNLOCK(fdp); 1483 stp->st_flags = 0; 1484 td->td_retval[0] = n; 1485 return (0); 1486 } 1487 1488 1489 static int 1490 pollout(td, fds, ufds, nfd) 1491 struct thread *td; 1492 struct pollfd *fds; 1493 struct pollfd *ufds; 1494 u_int nfd; 1495 { 1496 int error = 0; 1497 u_int i = 0; 1498 u_int n = 0; 1499 1500 for (i = 0; i < nfd; i++) { 1501 error = copyout(&fds->revents, &ufds->revents, 1502 sizeof(ufds->revents)); 1503 if (error) 1504 return (error); 1505 if (fds->revents != 0) 1506 n++; 1507 fds++; 1508 ufds++; 1509 } 1510 td->td_retval[0] = n; 1511 return (0); 1512 } 1513 1514 static int 1515 pollscan(td, fds, nfd) 1516 struct thread *td; 1517 struct pollfd *fds; 1518 u_int nfd; 1519 { 1520 struct filedesc *fdp = td->td_proc->p_fd; 1521 struct file *fp; 1522 #ifdef CAPABILITIES 1523 cap_rights_t rights; 1524 #endif 1525 int i, n = 0; 1526 1527 FILEDESC_SLOCK(fdp); 1528 for (i = 0; i < nfd; i++, fds++) { 1529 if (fds->fd > fdp->fd_lastfile) { 1530 fds->revents = POLLNVAL; 1531 n++; 1532 } else if (fds->fd < 0) { 1533 fds->revents = 0; 1534 } else { 1535 fp = fdp->fd_ofiles[fds->fd].fde_file; 1536 #ifdef CAPABILITIES 1537 if (fp == NULL || 1538 cap_check(cap_rights(fdp, fds->fd), 1539 cap_rights_init(&rights, CAP_EVENT)) != 0) 1540 #else 1541 if (fp == NULL) 1542 #endif 1543 { 1544 fds->revents = POLLNVAL; 1545 n++; 1546 } else { 1547 /* 1548 * Note: backend also returns POLLHUP and 1549 * POLLERR if appropriate. 1550 */ 1551 selfdalloc(td, fds); 1552 fds->revents = fo_poll(fp, fds->events, 1553 td->td_ucred, td); 1554 /* 1555 * POSIX requires POLLOUT to be never 1556 * set simultaneously with POLLHUP. 1557 */ 1558 if ((fds->revents & POLLHUP) != 0) 1559 fds->revents &= ~POLLOUT; 1560 1561 if (fds->revents != 0) 1562 n++; 1563 } 1564 } 1565 } 1566 FILEDESC_SUNLOCK(fdp); 1567 td->td_retval[0] = n; 1568 return (0); 1569 } 1570 1571 /* 1572 * OpenBSD poll system call. 1573 * 1574 * XXX this isn't quite a true representation.. OpenBSD uses select ops. 1575 */ 1576 #ifndef _SYS_SYSPROTO_H_ 1577 struct openbsd_poll_args { 1578 struct pollfd *fds; 1579 u_int nfds; 1580 int timeout; 1581 }; 1582 #endif 1583 int 1584 sys_openbsd_poll(td, uap) 1585 register struct thread *td; 1586 register struct openbsd_poll_args *uap; 1587 { 1588 return (sys_poll(td, (struct poll_args *)uap)); 1589 } 1590 1591 /* 1592 * XXX This was created specifically to support netncp and netsmb. This 1593 * allows the caller to specify a socket to wait for events on. It returns 1594 * 0 if any events matched and an error otherwise. There is no way to 1595 * determine which events fired. 1596 */ 1597 int 1598 selsocket(struct socket *so, int events, struct timeval *tvp, struct thread *td) 1599 { 1600 struct timeval rtv; 1601 sbintime_t asbt, precision, rsbt; 1602 int error; 1603 1604 precision = 0; /* stupid gcc! */ 1605 if (tvp != NULL) { 1606 rtv = *tvp; 1607 if (rtv.tv_sec < 0 || rtv.tv_usec < 0 || 1608 rtv.tv_usec >= 1000000) 1609 return (EINVAL); 1610 if (!timevalisset(&rtv)) 1611 asbt = 0; 1612 else if (rtv.tv_sec <= INT32_MAX) { 1613 rsbt = tvtosbt(rtv); 1614 precision = rsbt; 1615 precision >>= tc_precexp; 1616 if (TIMESEL(&asbt, rsbt)) 1617 asbt += tc_tick_sbt; 1618 if (asbt <= SBT_MAX - rsbt) 1619 asbt += rsbt; 1620 else 1621 asbt = -1; 1622 } else 1623 asbt = -1; 1624 } else 1625 asbt = -1; 1626 seltdinit(td); 1627 /* 1628 * Iterate until the timeout expires or the socket becomes ready. 1629 */ 1630 for (;;) { 1631 selfdalloc(td, NULL); 1632 error = sopoll(so, events, NULL, td); 1633 /* error here is actually the ready events. */ 1634 if (error) 1635 return (0); 1636 error = seltdwait(td, asbt, precision); 1637 if (error) 1638 break; 1639 } 1640 seltdclear(td); 1641 /* XXX Duplicates ncp/smb behavior. */ 1642 if (error == ERESTART) 1643 error = 0; 1644 return (error); 1645 } 1646 1647 /* 1648 * Preallocate two selfds associated with 'cookie'. Some fo_poll routines 1649 * have two select sets, one for read and another for write. 1650 */ 1651 static void 1652 selfdalloc(struct thread *td, void *cookie) 1653 { 1654 struct seltd *stp; 1655 1656 stp = td->td_sel; 1657 if (stp->st_free1 == NULL) 1658 stp->st_free1 = uma_zalloc(selfd_zone, M_WAITOK|M_ZERO); 1659 stp->st_free1->sf_td = stp; 1660 stp->st_free1->sf_cookie = cookie; 1661 if (stp->st_free2 == NULL) 1662 stp->st_free2 = uma_zalloc(selfd_zone, M_WAITOK|M_ZERO); 1663 stp->st_free2->sf_td = stp; 1664 stp->st_free2->sf_cookie = cookie; 1665 } 1666 1667 static void 1668 selfdfree(struct seltd *stp, struct selfd *sfp) 1669 { 1670 STAILQ_REMOVE(&stp->st_selq, sfp, selfd, sf_link); 1671 if (sfp->sf_si != NULL) { 1672 mtx_lock(sfp->sf_mtx); 1673 if (sfp->sf_si != NULL) 1674 TAILQ_REMOVE(&sfp->sf_si->si_tdlist, sfp, sf_threads); 1675 mtx_unlock(sfp->sf_mtx); 1676 } 1677 uma_zfree(selfd_zone, sfp); 1678 } 1679 1680 /* Drain the waiters tied to all the selfd belonging the specified selinfo. */ 1681 void 1682 seldrain(sip) 1683 struct selinfo *sip; 1684 { 1685 1686 /* 1687 * This feature is already provided by doselwakeup(), thus it is 1688 * enough to go for it. 1689 * Eventually, the context, should take care to avoid races 1690 * between thread calling select()/poll() and file descriptor 1691 * detaching, but, again, the races are just the same as 1692 * selwakeup(). 1693 */ 1694 doselwakeup(sip, -1); 1695 } 1696 1697 /* 1698 * Record a select request. 1699 */ 1700 void 1701 selrecord(selector, sip) 1702 struct thread *selector; 1703 struct selinfo *sip; 1704 { 1705 struct selfd *sfp; 1706 struct seltd *stp; 1707 struct mtx *mtxp; 1708 1709 stp = selector->td_sel; 1710 /* 1711 * Don't record when doing a rescan. 1712 */ 1713 if (stp->st_flags & SELTD_RESCAN) 1714 return; 1715 /* 1716 * Grab one of the preallocated descriptors. 1717 */ 1718 sfp = NULL; 1719 if ((sfp = stp->st_free1) != NULL) 1720 stp->st_free1 = NULL; 1721 else if ((sfp = stp->st_free2) != NULL) 1722 stp->st_free2 = NULL; 1723 else 1724 panic("selrecord: No free selfd on selq"); 1725 mtxp = sip->si_mtx; 1726 if (mtxp == NULL) 1727 mtxp = mtx_pool_find(mtxpool_select, sip); 1728 /* 1729 * Initialize the sfp and queue it in the thread. 1730 */ 1731 sfp->sf_si = sip; 1732 sfp->sf_mtx = mtxp; 1733 STAILQ_INSERT_TAIL(&stp->st_selq, sfp, sf_link); 1734 /* 1735 * Now that we've locked the sip, check for initialization. 1736 */ 1737 mtx_lock(mtxp); 1738 if (sip->si_mtx == NULL) { 1739 sip->si_mtx = mtxp; 1740 TAILQ_INIT(&sip->si_tdlist); 1741 } 1742 /* 1743 * Add this thread to the list of selfds listening on this selinfo. 1744 */ 1745 TAILQ_INSERT_TAIL(&sip->si_tdlist, sfp, sf_threads); 1746 mtx_unlock(sip->si_mtx); 1747 } 1748 1749 /* Wake up a selecting thread. */ 1750 void 1751 selwakeup(sip) 1752 struct selinfo *sip; 1753 { 1754 doselwakeup(sip, -1); 1755 } 1756 1757 /* Wake up a selecting thread, and set its priority. */ 1758 void 1759 selwakeuppri(sip, pri) 1760 struct selinfo *sip; 1761 int pri; 1762 { 1763 doselwakeup(sip, pri); 1764 } 1765 1766 /* 1767 * Do a wakeup when a selectable event occurs. 1768 */ 1769 static void 1770 doselwakeup(sip, pri) 1771 struct selinfo *sip; 1772 int pri; 1773 { 1774 struct selfd *sfp; 1775 struct selfd *sfn; 1776 struct seltd *stp; 1777 1778 /* If it's not initialized there can't be any waiters. */ 1779 if (sip->si_mtx == NULL) 1780 return; 1781 /* 1782 * Locking the selinfo locks all selfds associated with it. 1783 */ 1784 mtx_lock(sip->si_mtx); 1785 TAILQ_FOREACH_SAFE(sfp, &sip->si_tdlist, sf_threads, sfn) { 1786 /* 1787 * Once we remove this sfp from the list and clear the 1788 * sf_si seltdclear will know to ignore this si. 1789 */ 1790 TAILQ_REMOVE(&sip->si_tdlist, sfp, sf_threads); 1791 sfp->sf_si = NULL; 1792 stp = sfp->sf_td; 1793 mtx_lock(&stp->st_mtx); 1794 stp->st_flags |= SELTD_PENDING; 1795 cv_broadcastpri(&stp->st_wait, pri); 1796 mtx_unlock(&stp->st_mtx); 1797 } 1798 mtx_unlock(sip->si_mtx); 1799 } 1800 1801 static void 1802 seltdinit(struct thread *td) 1803 { 1804 struct seltd *stp; 1805 1806 if ((stp = td->td_sel) != NULL) 1807 goto out; 1808 td->td_sel = stp = malloc(sizeof(*stp), M_SELECT, M_WAITOK|M_ZERO); 1809 mtx_init(&stp->st_mtx, "sellck", NULL, MTX_DEF); 1810 cv_init(&stp->st_wait, "select"); 1811 out: 1812 stp->st_flags = 0; 1813 STAILQ_INIT(&stp->st_selq); 1814 } 1815 1816 static int 1817 seltdwait(struct thread *td, sbintime_t sbt, sbintime_t precision) 1818 { 1819 struct seltd *stp; 1820 int error; 1821 1822 stp = td->td_sel; 1823 /* 1824 * An event of interest may occur while we do not hold the seltd 1825 * locked so check the pending flag before we sleep. 1826 */ 1827 mtx_lock(&stp->st_mtx); 1828 /* 1829 * Any further calls to selrecord will be a rescan. 1830 */ 1831 stp->st_flags |= SELTD_RESCAN; 1832 if (stp->st_flags & SELTD_PENDING) { 1833 mtx_unlock(&stp->st_mtx); 1834 return (0); 1835 } 1836 if (sbt == 0) 1837 error = EWOULDBLOCK; 1838 else if (sbt != -1) 1839 error = cv_timedwait_sig_sbt(&stp->st_wait, &stp->st_mtx, 1840 sbt, precision, C_ABSOLUTE); 1841 else 1842 error = cv_wait_sig(&stp->st_wait, &stp->st_mtx); 1843 mtx_unlock(&stp->st_mtx); 1844 1845 return (error); 1846 } 1847 1848 void 1849 seltdfini(struct thread *td) 1850 { 1851 struct seltd *stp; 1852 1853 stp = td->td_sel; 1854 if (stp == NULL) 1855 return; 1856 if (stp->st_free1) 1857 uma_zfree(selfd_zone, stp->st_free1); 1858 if (stp->st_free2) 1859 uma_zfree(selfd_zone, stp->st_free2); 1860 td->td_sel = NULL; 1861 free(stp, M_SELECT); 1862 } 1863 1864 /* 1865 * Remove the references to the thread from all of the objects we were 1866 * polling. 1867 */ 1868 static void 1869 seltdclear(struct thread *td) 1870 { 1871 struct seltd *stp; 1872 struct selfd *sfp; 1873 struct selfd *sfn; 1874 1875 stp = td->td_sel; 1876 STAILQ_FOREACH_SAFE(sfp, &stp->st_selq, sf_link, sfn) 1877 selfdfree(stp, sfp); 1878 stp->st_flags = 0; 1879 } 1880 1881 static void selectinit(void *); 1882 SYSINIT(select, SI_SUB_SYSCALLS, SI_ORDER_ANY, selectinit, NULL); 1883 static void 1884 selectinit(void *dummy __unused) 1885 { 1886 1887 selfd_zone = uma_zcreate("selfd", sizeof(struct selfd), NULL, NULL, 1888 NULL, NULL, UMA_ALIGN_PTR, 0); 1889 mtxpool_select = mtx_pool_create("select mtxpool", 128, MTX_DEF); 1890 } 1891